Self-pressurized aerosol containers which dispense a liquid product such as an insecticide, room air freshener or deodorizer as an aerosol spray are well known and widely used because of their convenience. These containers are fitted with a valve which retains the contents of the container under pressure until the contents are needed. The contents of the container may be pressurized by different methods which include a pressurized gas or gases such as liquefied hydrocarbons such as propane, isopropane and isobutane, compressed gases such as nitrogen, air or carbon dioxide, and mechanical means such as expanding bags which force the contents out of the can when the valve is opened. The valve typically has a valve stem which extends to the outside of the container and has a hollow interior through which the contents of the container passes when the valve stem is moved to an open position.
To provide the desired degree of atomization to form an aerosol spray, an aerosol actuator button is tightly fitted over the valve stem. The actuator button contains a passageway ending in an orifice which is adapted to break the liquid stream coming from the interior of the container into aerosol droplets of the desired particle size. The user actuates the aerosol spray by pressing the button down or sideways to open the valve and allow the contents of the container to flow through the actuator button and out the orifice. The aerosol spray stops when the finger pressure on the button is removed. It is often convenient to make the actuator button a part of a larger overcap which is fixed onto the top of the self-pressurized container to provide an attractive and easy to use aerosol dispenser package. Examples of such aerosol actuator buttons, containers and overcaps for the same can be seen from an examination of U.S. Pat. No. 2,761,594 to Stroh; U.S. Pat. No. 3,138,295 to O'Donnell; U.S. Pat. No. 3,269,614 to Abplanalp; U.S. Pat. No. 3,373,908 to Crowell; U.S. Pat. No. 3,429,483 to Micallef; U.S. Pat. No. 3,642,179 to Micallef; U.S. Pat. No. 3,887,115 to Petterson; U.S. Pat. No. 4,068,782 to Van der Heijden; U.S. Pat. No. 4,378,081 to van Lit; and U.S. Pat. No. 4,805,839 to Malek.
U.S. Pat. No. 5,242,087 to Keldenich et al. teaches an aerosol overcap which has a locking lip that prevents spraying until an operating arm in the overcap is moved by exerting a force on a certain part of the overcap.
In many cases, an intermittent aerosol spray is all that is necessary. In other cases a continuous aerosol spray is desired. For example, insecticide fogging applications require that the entire contents of a self-pressurized container of insecticide be delivered as a fine aerosol spray or "fog" throughout an entire room.
One example of a continuous actuator can be seen from U.S. Pat. No. 4,428,509 to Emerson et al. where a safety tab is removed by the user and then the actuator button is pressed down to start the aerosol spray. The button is held down by a locking spur so that the entire contents of the self-pressurized container is dispensed. There is no provision for shutting off the aerosol spray once the actuator button has been pressed.
U.S. Pat. No. 4,941,600 to Berriochoa et al. teaches the use of a ring lock to hold the actuator button in the open position when it is depressed.
U.S. Pat. No. 4,440,325 to Treuhaft et al. teach an actuator button which is held in either the open or the closed position and is said to be easily movable between the two positions.
Other continuous spray actuators which require the user to remove the overcap or reposition some components thereof to achieve continuous spray are described in U.S. Pat. No. 3,137,414 to Steinkamp; U.S. Pat. No. 3,424,354 to Dykinga; U.S. Pat. No. 3,765,573 to Landsman; U.S. Pat. No. 4,186,853 to White; and U.S. Pat. No. 4,195,756 to Campbell.
U.S. Pat. No. 3,305,144 to Beres et al. teaches an aerosol dispenser that has a removable valved conduit for spraying. The valve on the self-pressurized container is held in its open position by an adapter that fits over the valve stem of the container.
U.S. Pat. No. 4,381,065 to Hayes teaches a one piece molded overcap with a discharge actuator that is tabbed to the overcap shell. The tabs are broken and the discharge actuator is folded over to where it is held by detents to provide a continuous aerosol spray. The discharge actuator is lifted to stop the continuous spray.
For certain products such as insecticides, it may also be desirable to provide an overcap which is capable of dispensing the contents of the self-pressurized container either intermittently or continuously as the user desires. Various approaches have been taken to provide such overcaps.
U.S. Pat. No. 4,679,713 to Crapser et al. teaches an aerosol actuator overcap which permits both intermittent and continuous spraying. Intermittent spraying is accomplished by simply pressing on the actuator button. Continuous spraying is accomplished by twisting the outer portion of the overcap so that the actuator button is cammed into a continuous spraying position. One disadvantage of this overcap is that it has several parts which must be fitted together during manufacture. That increases the cost of the overcap as well as the time needed to manufacture the aerosol container.
U.S. Pat. No. 3,185,350 to Abplanalp et al. teaches a an overcap which locks the actuator button from dispensing the contents of the container when the overcap is rotated to one position. Rotation to different positions permits either continuous spray or intermittent spray.
U.S. Pat. No. 3,519,173 to Sagarin teaches a dual function aerosol actuator overcap. When the actuator button is pressed downward, an intermittent spray is obtained which stops when the pressure on the actuator button is released. However, the actuator button may also be tilted or rocked at the same time it is depressed to cause cooperable shoulder portions to become engaged by an interference action and thus prevent return of the actuator button to its normal non-spraying position. The contents of the container are then continuously dispensed until the user again depresses the actuator button and, at the same time, rocks or tilts the button to disengage the cooperable shoulder portions. The actuator button can then return to its normal non-spraying position and the aerosol spray is stopped. However, operation of this aerosol actuator overcap does require some dexterity in pushing down as well as rocking or tilting the actuator button to engage and disengage continuous spraying.
U.S. Pat. No. 3,081,918 to Scoggin, Jr. et al. and U.S. Pat. No. 3,901,412 to Copia use similar actuator buttons to provide intermittent and continuous aerosol dispensing. They employ an actuator button that has a hook that snaps over the edge of the valve when a continuous aerosol spray is desired. To stop the spray, the hook is released by pressing against one side of the actuator button.
U.S. Pat. No. 3,178,077 to Benedetto teaches an actuator button which can be intermittently sprayed by pressing a trigger partly down. Fully depressing the trigger causes engagement with a snap extension which holds the actuator button in its open position. The user presses against the snap extension to release the trigger and stop the spray.
U.S. Pat. No. 3,894,665 to Swenson teaches a safety overcap for an aerosol container which also contains a locking device that permits continuous spraying. However, the sides of the overcap must be squeezed to release the actuator button from its continuous spray position.
U.S. Pat. No. 4,260,080 to Gailitis teaches a mushroom-shaped overcap that can be set to continuous spray when one end of the overcap is pushed down so that it engages the edge of the container. Pressure on the opposite side of the overcap releases the edge engagement to stop the continuous aerosol spray. Gailitis teaches that his overcap has the advantage that the user only needs one hand to discontinue the aerosol spray.
Although aerosol actuator overcaps are described in the prior art, there is still a need for a simple to make and use dual function aerosol actuator overcap.